Laundry Guide

MY Hospitality Supplies has been in the manufacturing and distribution of Bed Linens, Towels, Table Linens, Health Care Linens and, Uniforms for over 25 years. During that period we have owned and operated commercial laundries that served major hotels, hospitals, restaurants, etc. Our research labs had the responsibility to find methods to reduce the costs of all factors that a large laundry would incur, such as; labor, supplies, utilities, and most important, the life of the textiles we laundered.MY Hospitality Supplies is no longer in the commercial laundry phase of the industry, we concentrate on the mfg and distribution of institutional linens at the lowest price possible now from our Own Manufacturing Plant In China, India and Pakistan. What we learned from our years of research and experience we now offer to you our customers, so that you may find ways in your operation to save considerable costs and increase the life of the textiles we provide you with. If you need any help with your laundry operation or would like some good Free Advice on how to set up an In-House laundry, Contact us at save@myhospitalitysupplies.com

The most important thing you can do in the laundry is to use the correct detergent for the classification of soiled items you are washing. Hotel towels and bed linens do not require nor is it desirable to use the same detergent as used for kitchen towels and apparel. Hospital, Health Care Linens, with the exception of some contaminated linens, require another detergent.

Why is the detergent so important? Because, the correct detergent will require less water temperature, and shorter wash cycles, and clean the fabric better than an incorrect product. Certain detergents can leave the fabric less wet…thereby reducing drying time and cost. Other formulations can eliminate the need to iron sheets and pillow cases, thus saving dramatically in labor and utilities. We will go into detail on these factors but, first let us look into the chemistry involved. Once you understand the chemistry you can with your chemical supplier or formulator select a formulation that will reduce all your costs and increase the life of your linens. To start here is the difference in detergents, both Ionic and nonionic.

The difference between anionic and nonionic surfactant:
Surfactant is a substance which has both a hydrophilic group and a hydrophobic group. Concerning the name, a surfactant which dissociates in water and releases caution and anion (or zwitterions) is termed ionic (cationic, anionic, zwitterionic) surfactant. On the other hand, a surfactant which does not dissociate is called a nonionic surfactant. An anionic surfactant has an anionic hydrophilic group. Examples of anionic surfactants are generally called alkyl sulfonic acid salts (the main component of synthetic detergent, such as linear alkyl benzene sulfonate (LAS)), fatty alcohol sulfate (the main component of shampoo or old neutral detergents), Because fatty acid soap is a salt of fatty acid and alkali metal (a salt of a weak acid and a strong base), it hydrolyzes in water and the solution becomes slightly basic. However, the solutions of other anionic surfactants are neutral. The solution of synthetic detergent is adjusted to slightly basic, but this is not because of the detergent itself (it is neutral) but because of the effect of auxiliary agents (sodium carbonate, etc). This is the main difference between soap and synthetic detergent.

It has been known since early times that dirt is washed off by alkali, such as lye and washing soda. Detergents on the market (both powder soap and synthetic detergent) would have the same effect, since the liquids are alkaline when they dissolve in water. It is thought that fibers (laundry) are softened by alkali, causing the release of dirt. So it is ineffective to wash poor alkali-proof animal fiber, such as silk and wool with alkali. It is also thought that alkali cleans off oily dirt by saponification reaction (formation of water-soluble soap), which is the same as the synthesis of soap. However, it is doubtful whether this reaction really occurs during home washing.

Animal fibers, such as silk and wool, are called, amphoteric fibers, which means that the fibers can become both cationic and anionic, depending on the property of the liquid. If alkaline detergents (both powder soap and synthetic detergent) are used for washing these fibers, anionic surfactant would adsorb on the cationic groups (amino groups) on the fiber.

It would be possible to wash poor alkali-proof fiber by maintaining a neutral pH. However, we cannot do anything about the ionic adsorption of surfactant on fibers. This is one of the advantages of non-ionic surfactants. There is a detergent that can wash clothes which have the “dry cleaning sign” (the picture sign for recommending that dry cleaning be done, found on silk and wool products) by water at home. As you may already realize, the main component of this type detergent is non-ionic surfactant. Since electrostatic force does not work for non-ionic surfactants, the amount of detergent remaining after washing would be low for other kinds of clothes as well as for silk and wool.

There is a possibility that anionic surfactants combine with cationic ions, for example, calcium ion in hard water. Especially in the case of powder soaps, fatty acids combine with calcium ions and form scum, which is not water-soluble and precipitates, decreasing the cleaning effect. Other anionic surfactants also combine with calcium, but these amounts would be low. Anyway, no precipitation happens if non-ionic surfactant is used. So this point is also one of the advantages of non-ionic surfactants.

Two in One (Conditioner & Shampoo)was popular a short time ago. This was a shampoo, which did not require the use of another conditioner. Conditioner serves a similar function as softener for washing clothes, so the main component of a conditioner is cationic surfactant, which resembles fabric softener. This means that it is impossible to mix conditioner agents with regular shampoo. If you mix shampoo and conditioner in the bathroom, you may see precipitation like scum. This is caused by combination of the cationic surfactant with the anionic surfactant. Of course, this precipitation does not do anything.

There were three kinds of
1) Just conditioner whose cationic surfactant has some detergency.
2) Just shampoo in which the oil content is blended.
3) Real Conditioner & Shampoo, i.e., the main surfactant of shampoo does not combine with the cationic surfactant of the conditioner.

You could easily guess that the surfactant used in 3) is non-ionic surfactant. The same concept was applied to a detergent for washing clothes, and now the detergents containing fabric softeners are widely used. The main component of this type of detergent has to be non-ionic surfactant. Non-ionic surfactant can be used with many kinds of auxiliary agents, making non-ionic surfactants very advantageous.

Application of non-ionic surfactant to detergent for clothes, consider why non-ionic surfactants, which seem to have many advantages, have not been used for detergents up to now. All surfactants which can be used for food (according to food hygiene law in Japan) are non-ionic surfactants, except for soybean phospholipid (lecithin, an amphoteric surfactant). It is thought that they are harmless because they are fatty acid esters of polyalcohol such as sorbitan, sucrose, and glycerin. So it would be wonderful if we could apply these surfactants to laundry. I did an experiment however, hardly any dirt was cleaned off by sucrose fatty acid ester. Thus, the detergency of the non-ionic surfactant was weak I did a further experiment and found a non-ionic surfactant which does possess a certain level of detergency. However, making it difficult to use. This surfactant could be usefully applied to liquid detergent, but it was not the trend to use liquid detergent, and additionally it dripped, making it difficult to handle, and so it did not become common. Since non-ionic surfactants can be easily synthesized, they are used in many fields now. However, non-ionic surfactants were not used as the main surfactant of synthetic detergent for laundry until the powder form of non-ionic surfactant (polyoxyethylene) was invented.

I found that liquid crystal was formed during the washing process of oily dirt and the liquid crystal contributed to removing the dirt. And I established the new method to indicate the effectiveness of washing (kinetics of wash). I measured the speed of liquid crystal formation and the washing speed. When I used the non-ionic surfactant (polyoxyethylene) for the experiment, I found that the liquid crystal was formed at lower concentration and lower temperature (compared to anionic surfactant). This experiment was published, and around the same time a manufacturer invented the powder form of non-ionic surfactant (polyoxyethylene). So powder compact detergent, whose main component was non-ionic surfactant, was released by a major detergent manufacturer with the motto, liquid crystal cleans off dirt. However, the detergent was discontinued a few years after its release probably because consumers at that time were not very environmentally conscious.

The use of detergent whose main components are non-ionic surfactants is increasing. This increase is related not only to the advantages mentioned above but also to the effect of its good image. Since in recent times most clothes do not get as dirty as they once did, and at the same time that environmental concern is increasing, an environmentally friendly detergent, even one with decreased dirt cleaning power, can be accepted by modern society.

The detergency behavior towards nonpolar soil was modelled for seven technical nonionic surfactant as a function of surfactant concentration, washing time and washing temperature. The detergency experiments were carried out according to a central composite circumscribed statistical experimental design. Second order polynomial functions were used for the modelling. It was possible to establish good models for all surfactants except one. For three of the surfactants the models predicted a detergency maximum. The detergency effects of these surfactants were examined at the variable settings predicted to give maximum detergency. The results obtained were in good agreement with predictions. The surfactant concentration giving maximum detergency is not directly linked to the c. m. c. The temperature for maximum detergency corresponds to the cloud point of the washing solution with the surfactant concentration giving maximum detergency. The cloud point has to be determined with the soil present. This indicates that a micro emulsion has to be present to obtain maximum nonpolar soil removal.

GENERAL REQUIREMENTS FOR DETERGENT AND CLEANING PRODUCTS:
Detergents and cleaning products should offer an outstanding cleaning performance at an affordable price, allowing a low water and energy usage during the cleaning process and involving as few extra cleaning steps as possible via a process where stains and soils are removed without additional intervention like rubbing, soaking, pretreating or rewashing, in the case of clothes washing. In addition, existing legislation and the future Detergent Regulation, which is about to go to 2nd reading in the European Parliament imposes requirements on the environmental properties of surfactants. If these criteria are not met, the substance cannot be used in household detergent and cleaning products. If they are met there can be no real differentiation between individual surfactant substances and no substitutions needed (nor can any claim of superiority be upheld). All are equally safe for the environment. The leveling process is the sewage works, where effective biodegradation occurs with all currently used consumer surfactants. , Surfactants do differ in various ways – molecular structure, physical and biologically relevant properties – but, due to the legally required high level of biodegradation in sewage treatment, the differences, as far as the environment is concerned, are minimal. ERASM worked with the Dutch Government some years ago to demonstrate the great effectiveness of sewage treatment in degrading all commonly used surfactants.

Detergents and cleaning products depend upon surfactants for their cleaning. Surfactants are often referred to as the “engine” of the detergent system. They can be present at low levels (<5%) as well as in considerably higher levels (e.g. 20-30%) in concentrated products. They wet the fabrics and soils and so allow the removal of soils and dirt. They suspend a whole range of stains and dirt (particulate, greasy, body soils, cosmetics). However, for laundry and machine dishwashing, other ingredients are also essential such as water softeners (zeolite; phosphate, citrate etc.), bleaching systems (percarbonate, bleach activators), dirt suspension agents (polymers, ..), enzymes, chelating agents, perfumes, etcetera. For other types of cleaners, other formulation ingredients are required such as solvents etc.

PARAMETERS AFFECTING CLEANING PERFORMANCE AND SURFACTANCY/DETERGENCY PROPERTIES:
It is also essential to consider factors such as the interaction, compatibility and synergy of the various ingredients used in detergents, e.g. interactions between anionic and nonionic surfactants, between surfactants and builders, enzymes or the bleaching system, etc. of the individual raw materials during the manufacturing process is key (easiness to transport, store, handle,…) and this for the production for each of the forms of detergents, such as granular, liquid and tablet products. Finally, the formulated detergent and cleaning products must also have an outstanding stability profile (e.g. stabilization of enzyme or bleach system). surfactants, others as co-surfactants, known also as “specialty surfactants” (smaller usage and higher price versus mainframe surfactants). Co-surfactants are typically blended at low levels with mainframe surfactants for synergistic effects. In general, there are several reasons why a broad range of surfactants is needed. The surface activity of surfactants (and thus cleaning power) increases with longer alkyl chain lengths. However, this results in decreased solubility and possible loss of the surfactant via precipitation in hard and cold water. Shorter chain surfactants have superior solubility but reduced surface activity, and thus reduced cleaning performance. Insolubility and precipitation effects can be overcome in many cases by formulating with extra detergent ingredients such as builders or the introduction of co-surfactants and/or polymers.

The surfactant system must be effective in the range of cleaning conditions described above such as a range of water hardness and soil/stains conditions,… and this for various types of product forms (liquid, tablet, granular). There is also a need to adapt to changing consumer habits. For example, long chain linear C 16/18 alcohol sulfates were widely used around 1960/70, but other alcohol sulphates (for example with shorter chainlength) or other surfactant types were introduced when wash habits moved from boil wash temperatures to cooler temperatures and when other changes in the detergent composition occurred (e.g. changes in use of water hardness builders).

Surfactants can be derived from petrochemical feedstocks, as well as from oleochemical feedstocks, or from a mixture of both (surfactant alcohol from oleochemical; ethylene oxide from petrochemical). In all cases, they will exceed stringent environmental and health criteria. The cost and availability of oleochemical and petrochemical materials can change regularly since these markets are associated with the global food/fat market, and the petroleum/energy market, respectively. However, for some oleochemically derived nonionics like APG, the cost and performance profile do not make them overly attractive and certainly not a viable replacement for LAS.

EASE OF SUBSTITUTION:
There are numerous examples that demonstrate that each surfactant class and type has a specific profile, with strengths under certain application conditions, but also limitations or shortcomings under other conditions. Some examples are described here. Linear Alkylbenzene Sulphonate (LAS) cannot simply be substituted by alcohol sulphates (AS) in detergents: for laundry detergents, alkyl sulphates (AS) can produce more sudsing during the wash process and require specific suds suppressor systems.

Besides sudsing, there are also solubility considerations that have to be taken into account: alkyl sulphates (AS) with chainlengths predominantly in the 12-14 C-range (derived from coconut oil, palm kernel oil or petrochemically produced) could produce too much sudsing, while alcohol sulphates (AS) with chainlenghts predominantly in the 16-18 C-range (palm oil derived) can lead to insolubility issues. In liquid detergents, more solvent would be required to stabilize alcohol sulphates (AS) (versus LAS). In addition, the processing of AS in laundry detergents can be more demanding than LAS since it is more prone to hydrolysis. Whilst it is also known that alcohol ethoxy sulphates (AES) are more suitable for cutting grease and are less hardness sensitive than LAS, these properties are most important for hand dishwashing applications.

This points to the fact that a range of surfactants are required to meet consumer needs in an optimal fashion, and that reduction in choice of surfactants, provided environmental and human safety are assured, is not either proportionate or beneficial. In laundry detergents, performance is optimised by the use of a mixture of anionic and nonionic surfactants. Formulations with only anionic surfactants or only nonionic surfactants result in inferior cleaning performances and suffer from other limitations. The use of mixtures of anionic and nonionic surfactants in detergent formulators helps to achieve an optimum cleaning performance, through optimised surfactant ‘packing’ at the fabric interface, better anti-redeposition properties, water hardness tolerance through preventing the precipitation of insoluble calcium salts of anionics. Raw material and detergent processing is also improved.

Whilst nonionic surfactants can contribute significantly to the removal of greasy stains, they exhibit poor cleaning performance due to poor ‘packing’ of the water/fabric interface and in addition, they have a considerably lower ability to suspend particulates in the wash liquor, which is essential to avoid the redeposition of soils from the washing solution onto the fabrics.

Manufacturing powdered detergents with only nonionic surfactants is technologically more difficult, since nonionic surfactant raw materials are typically available in a waxy or liquid form, which is convenient for transport and handling, but not optimal for use as the only surfactant in granular detergents. Anionic surfactants are typically available in a solid form (after the surfactant neutralisation step from their ‘acid’ version into the Na-salts), and a mixture of anionic and nonionic surfactants are best for an efficient production of granular detergents.

CONCLUSION:
The described examples show that there is a need to use mixtures of anionic and nonionic surfactants in detergent formulators in order to achieve an optimum across all important parameters, such as cleaning performance, ‘packing’ at the fabric interface, anti-redeposition properties, water hardness tolerance, etc.

In terms of economics, there are significant cost differences between commercially available surfactants. For example, LAS is one of the most commonly used ‘workhorse’ surfactants and it is highly cost-effective. Even is 1-for-1 replacement is not possible based on the above arguments, such a theoretical substutition on an equal weight basis by other surfactants can lead to a 10-15% cost increase for the surfactant system.

The challenge to the detergent industry is how to optimize the overall cleaning power to better address the demanding and evolving wash habits and consumer needs, both amongst high income and low income groups in society. Getting the engine of the detergent right, namely the surfactant system, is essential in this context.

Now you know everything and more about detergents than you will ever need. However this knowledge properly utilized will save your company a great deal of time and money. You cannot purchase the correct detergents or other laundry compounds unless you know more than the person selling them to you. We reduced our overall costs more than 52% by using proper formulations. You can do the same.